Carrier body for a grinding or a cutting tool

ABSTRACT

Carrier body (1) for a grinding or a cutting tool (2), comprising a central coupling area (3) for connecting the grinding or cutting tool (2) to a rotary drive for rotating the grinding or cutting tool (2) about an axis of rotation (4) passing through the coupling area (3), a carrier structure (6) adjacent thereto in the radial direction (5), wherein the carrier structure (6) has recesses (7, 8) separate from the coupling area (3), and two substantially annular side surfaces (9, 10) which are spaced apart from each other in the axial direction (11) across the carrier structure (6), wherein at least some, preferably all, of the recesses (7, 8) are open only to one of the side surfaces (9, 10) of the carrier body (1).

The invention relates to a carrier body for a grinding or a cutting tool, comprising a central coupling area for connecting the grinding or cutting tool to a rotary drive for rotating the grinding or cutting tool about an axis of rotation passing through the coupling area, a carrier structure adjacent thereto in the radial direction, wherein the carrier structure has recesses separate from the coupling area, and two substantially annular side surfaces which are spaced apart from each other in the axial direction across the carrier structure. The invention furthermore relates to a grinding or a cutting tool with such a carrier body and an abrasive material arranged in or on the carrier body.

Such a carrier body is for example known from EP 2 810 739. Here recesses, which are formed as lead-throughs, are arranged in the carrier structure. With this design, a carrier body with a particularly low weight is to be achieved. However, it has been observed that the lead-throughs lead to undesired noise generation and, when a coolant is used, to negative effects on the operating characteristics, e.g. imbalance, due to turbulence and deflection of the coolant. In order to eliminate these disadvantages, the lead-throughs are sealed on both sides with covering elements.

The production of the carrier body is, however, very elaborate as, in a first working step, the carrier body has to be provided with lead-throughs, in a second working step, a first covering element has to be applied to one side of the lead-throughs and finally, in a third working step, a further covering element has to be applied to the other side of the lead-throughs.

The application of the covering elements itself is also very elaborate as, on the one hand, only a bonding in the inner area of the carrier body is effected and, on the other hand, a gap to the casing body is created in the radial direction. Both steps require high precision during the processing.

In addition, removed material can collect in the gaps between the covering elements and the casing body and can thus significantly impair the grinding properties. Through the gap, there is even a risk that when a coolant is used the coolant will collect in the lead-throughs, thereby resulting in an imbalance of the carrier body.

The object of the present invention is to indicate a carrier body which is improved compared with the state of the art, can be produced in particular more simply and inexpensively and has an increased lifetime with substantially constant grinding properties, as well as a grinding or cutting tool with such a carrier body which is improved compared with the state of the art.

This object is achieved by the features of claims 1 and 15.

In the case of the carrier body according to the invention, it is therefore provided that at least some, preferably all, of the recesses are open only to one of the side surfaces of the carrier body.

These are therefore one-sided recesses, which can be produced for example by milling or drilling. In comparison with the state of the art, instead of three working steps only one working step is necessary. This asymmetrical formation of the recesses is already sufficient to considerably reduce the noise generation.

Surprisingly, the asymmetry has no adverse effects on the operating characteristics of the carrier body or of a grinding or cutting tool produced therewith, which a person skilled in the art would thus not have expected.

Moreover, a person skilled in the art would also therefore not have considered such a formation against the background of EP 2 810 739 as in this specification it is explicitly pointed out that the radial elasticity of the carrier body is lost by a complete sealing of the lead-throughs. By comparison, it has transpired that the radial elasticity is retained to an adequate extent in the case of the one-sided opening of the recesses according to the invention.

According to a preferred embodiment, it is provided that the recesses are open to the same side surface of the carrier body. This is advantageous insofar as the carrier body has to be machined only from one side to produce the recesses.

It has furthermore proven favourable that the recesses are sealed on the side surface which is opposite the side surface, to which the recesses are open, by a side wall which is connected to the carrier structure in one piece, preferably wherein, in the axial direction, the side wall has a thickness of from 0.3% to 15%, preferably approx. 10%, of the thickness of the carrier body.

In order when using a coolant to prevent turbulence of the coolant, according to preferred embodiments the steps defined in dependent claims 5 to 9 can be carried out. By means of these steps, either alone or in combination with each other, it is possible to benefit from the advantages achieved by the asymmetrical formation of the recesses also in the case of carrier bodies in which a coolant is to be used, without turbulence of the coolant arising.

Further particularly advantageous embodiments are contained in dependent claims 10 to 14.

As stated at the beginning, protection is also sought for a grinding or cutting tool with a carrier body according to the invention and an abrasive material arranged in or on the carrier body, preferably wherein the carrier body has a peripheral surface and the abrasive material is arranged in the form of an abrasive layer on the peripheral surface of the carrier body.

The abrasive material can be for example CBN or diamond. The abrasive layer can be applied on the peripheral surface using conventional bonding systems, for example by means of a galvanic coating, or by means of bonded or soldered-on abrasive segments with ceramic bonding matrix, or synthetic resin or metal bonding.

Further details and advantages of the invention are explained in more detail in the following by means of the description of the figures with reference to the drawings. There are shown in:

FIG. 1a a carrier body for a grinding or cutting tool according to a first preferred embodiment example in a top view onto a side surface,

FIG. 1b the carrier body according to FIG. 1a in a top view onto the opposite side surface,

FIG. 2 the carrier body according to FIGS. 1a and 1b in a cross-sectional view along the cross-sectional plane 27 drawn in in FIG. 1 a,

FIG. 3 a carrier body for a grinding or cutting tool according to a second preferred embodiment example in a cross-sectional view,

FIG. 4 a carrier body for a grinding or cutting tool according to a third preferred embodiment example in a cross-sectional view, and

FIG. 5 a grinding or cutting tool with a carrier body according to a fifth preferred embodiment example and an abrasive material in a cross-sectional view.

The carrier body 1 for a grinding or a cutting tool represented in FIGS. 1a, 1b and 2 comprises a central coupling area 3 for connecting the grinding or cutting tool formed with the carrier body 1 to a rotary drive for rotating the grinding or cutting tool about an axis of rotation 4 passing through the coupling area 3. Here the coupling area 3 can have a central lead-through 20 which can, for example, accommodate a driveable spindle. For the torque-proof connection of the grinding or cutting tool to the rotary drive, means 21, 22 can additionally be provided, which are arranged neighbouring the lead-through 20. The means 21, 22 can be, for example, lead-throughs for the accommodation of screws or the like.

In the radial direction 5, a carrier structure 6 is adjacent to the coupling area 3. The carrier structure 6 has recesses 7, 8 separate from the coupling area 3. The recesses 7, 8 can have quite different cross-sectional shapes. In the case of the carrier body 1 represented in FIGS. 1a, 1b and 2, the recesses 7 have a circular cross section in a cross-sectional plane 19 normal to the axis of rotation 4. The recesses 8 have a slotted hole-shaped cross section.

The carrier body 1 furthermore comprises two substantially annular side surfaces 9, 10, which are spaced apart from each other in the axial direction 11 across the support structure 6. If the carrier body 1 is regarded as a circular cylinder with two cylinder end surfaces and a lateral surface, the side surfaces 9, 10 are therefore part of the cylinder end surfaces.

The recesses 7, 8 are open only to one of the side surfaces 9, 10 of the carrier body 1. More precisely, the recesses 7, 8 are open to the same side surface, namely the side surface provided with the reference number 9, of the carrier body 1.

On the side surface 10 which is opposite the side surface 9, to which the recesses 7, 8 are open, the recesses 7, 8 are sealed by a side wall 12, which is connected to the carrier structure 6 in one piece. This means that, in the case of a top view onto the side surface 10 of the carrier body 1, it is only possible to see through the lead-throughs 20, 21, 22. Apart from that, the carrier body 1 presents itself as a substantially closed surface.

It has proven advantageous that, in the axial direction 11, the side wall 12 has a thickness 13 of from 0.3% to 15% of the thickness 14 of the carrier body 1. In the case represented, the side wall 12 has a thickness 13 in the axial direction 11 of approx. 10% of the thickness 14 of the carrier body 1.

In order to keep the weight of the carrier body 1 as low as possible and at the same time to achieve sufficient stability, it is possible for the recesses 7, 8 on the side surface 9, to which the recesses 7, 8 are open, to occupy a total area of from 50% to 90%. In the case represented, the recesses 7, 8 on this side surface 9 occupy a total area of approx. 75% of the side surface 9.

The carrier body 1 is formed asymmetrically relative to the centre plane 26 normal to the axis of rotation 4. This fundamentally differentiates it from the carrier bodies known from the state of the art.

The advantages of the structure according to the invention of the carrier body 1 are particularly evident in the case of carrier bodies with a comparatively large diameter of from 250 mm to 700 mm. In the case represented, the carrier body 1 has a diameter 23 of approx. 400 mm.

The thickness 14 of the carrier body 1 in the axial direction 11 can be, for example, from 20 mm to 300 mm. In the case represented, the carrier body 1 has a thickness 14 in the axial direction 11 of approx. 30 mm.

The embodiment example according to FIG. 3 differs from the embodiment example according to FIGS. 1a, 1b and 2 in that the recesses 7, 8 on the side surface 9, to which the recesses 7, 8 are open, are covered by an annular cover 15. This cover 15 is used to prevent turbulence of a coolant used to cool the carrier body 1. In addition, the cover 15 reduces still further the generation of noise in the grinding or cutting insert. Turbulences in the air are also prevented.

The cover 15 is bonded to the side surface 9, to which the recesses 7, 8 are open. In comparison with the state of the art, there is a bonding at every point at which the cover 15 contacts the side surface 9. In this way, the recesses 7, 8 can be reliably covered.

The side surface 9, to which the recesses 7, 8 are open, has a cut-out 16 which has a shape corresponding to the cover 15. This means that the cut-out 16 in the case represented is also annular.

The cover 15 is inserted in this cut-out 16 substantially without gaps. This fact also represents a difference from the state of the art, where there was still a preconception that a gap had to be left to the casing body in order to guarantee the radial elasticity of the carrier body 1.

In the axial direction 11, the cover 15 can have a thickness 17 of from 0.3% to 15% of the thickness 14 of the carrier body 1. In the case specifically represented, in the axial direction 11, the cover 15 has a thickness 17 of approx. 10% of the thickness 14 of the carrier body 1.

The embodiment example represented in FIG. 4 differs from the embodiment example represented in FIG. 3 in that the recesses 7, 8 are filled with a filler material 18 in the form of synthetic resin. This filler material 18 essentially has the same function as the cover 15, which is used in the case of the embodiment example according to FIG. 3.

FIG. 5 shows a grinding tool 2 which has a carrier body, wherein the carrier body comprises a peripheral surface 25. An abrasive material 24 in the form of an abrasive layer is arranged on the peripheral surface 25. The carrier body is substantially formed like the carrier body 1 according to FIGS. 1a, 1b and 2, with the difference that no cut-out 16 is provided. A further difference consists in that the peripheral surface 25 is formed smooth. The shape of the peripheral surface 25 is, however, arbitrary, and can be chosen differently according to the application.

In principle, it should also be pointed out that the features of the cut-out 16, the cover 15 and the filler material 18 can be combined with each other as desired. 

1. Carrier body (1) for a grinding or a cutting tool (2), comprising a central coupling area (3) for connecting the grinding or cutting tool (2) to a rotary drive for rotating the grinding or cutting tool (2) about an axis of rotation (4) passing through the coupling area (3), a carrier structure (6) adjacent thereto in the radial direction (5), wherein the carrier structure (6) has recesses (7, 8) separate from the coupling area (3), and two substantially annular side surfaces (9, 10) which are spaced apart from each other in the axial direction (11) across the carrier structure (6), characterized in that at least some, preferably all, of the recesses (7, 8) are open only to one of the side surfaces (9, 10) of the carrier body (1).
 2. Carrier body (1) according to claim 1, wherein the recesses (7, 8) are open to the same side surface (9) of the carrier body (1).
 3. Carrier body (1) according to claim 1, wherein the recesses (7, 8) are sealed on the side surface (10) which is opposite the side surface (9), to which the recesses (7, 8) are open, by a side wall (12) which is connected to the carrier structure (6) in one piece.
 4. Carrier body (1) according to claim 3, wherein, in the axial direction (11), the side wall (12) has a thickness (13) of from 0.3% to 15%, preferably approx. 10%, of the thickness (14) of the carrier body (1).
 5. Carrier body (1) according to claim 1, wherein the recesses (7, 8) are covered on the side surface (9), to which the recesses (7, 8) are open, by a common, preferably annular, cover (15).
 6. Carrier body (1) according to claim 5, wherein the cover (15) occupies a larger portion of the side surface (9) than the recesses (7, 8), and/or the cover (15) is bonded to the side surface (9), to which the recesses (7, 8) are open, preferably wherein there is a bonding at every point at which the cover (15) contacts the side surface (9).
 7. Carrier body (1) according to claim 5, wherein the side surface (9), to which the recesses (7, 8) are open, has a cut-out (16), which has a shape corresponding to the cover (15), and the cover (15) is inserted into the cut-out (16) substantially without gaps.
 8. Carrier body (1) according to claim 5, wherein, in the axial direction (11), the cover (15) has a thickness (17) of from 0.3% to 15%, preferably approx. 10%, of the thickness (14) of the carrier body (1).
 9. Carrier body (1) according to claim 1, wherein the recesses (7, 8) are filled, at least in areas, preferably completely, with a filler material (18), preferably synthetic resin.
 10. Carrier body (1) according to claim 1, wherein the recesses (7, 8) have a circular or slotted hole-shaped cross section in a cross-sectional plane (19) normal to the axis of rotation (4).
 11. Carrier body (1) according to claim 1, wherein the recesses (7, 8) on the side surface (9), to which the recesses (7, 8) are open, occupy a total area of from 50% to 90%, preferably approx. 75%, of the side surface (9).
 12. Carrier body (1) according to claim 1, wherein the coupling area (3) has a central lead-through (20), and preferably means (21, 22) for the torque-proof connection of the grinding or cutting tool (2) to the rotary drive, wherein the means (21, 22) for the torque-proof connection are arranged neighbouring the lead-through (20).
 13. Carrier body (1) according to claim 1, wherein the carrier body (1) has a diameter (23) of from 250 mm to 700 mm, preferably approx. 400 mm, and/or a thickness (14) in the axial direction (11) of from 20 mm to 300 mm, preferably approx. 30 mm.
 14. Carrier body (1) according to claim 1, wherein the carrier body (1) is formed asymmetrically relative to a centre plane (26) normal to the axis of rotation (4).
 15. Grinding or cutting tool (2) with a carrier body (1) according to claim 1 and an abrasive material (24) arranged in or on the carrier body (1), preferably wherein the carrier body (1) has a peripheral surface (25) and the abrasive material (24) is arranged in the form of an abrasive layer on the peripheral surface (25) of the carrier body (1). 